The present invention relates to a container for a fluid and more particularly to a container effective for a liquid having a high viscosity.
As a container for a liquid there has been known, as shown in FIG. 13, a bag-in-box type container (hereinafter referred to as "BIB container") comprising a rigid, outer container 50 formed of a hard paperboard and a soft, inner container (inner bag) 51 constituted by a flexible bag and disposed within the outer container.
In the BIB container, the outer container 50 protects the container against external impact, etc. while retaining a predetermined box shape, and by contraction of the inner container 51, a liquid 52 as the contents of the inner container 51 can be withdrawn from a discharge port 53.
In the case where a liquid having a high viscosity, e.g. ink, is contained in the BIB container, it can be withdrawn from the inner container 51 by providing a suction nozzle in the portion of the discharge port 53 and by suction of the liquid using a pump or the like.
In the conventional BIB container, however, the inner bag 51 is deformed irregularly during withdrawal of the liquid 52 from the interior of the container, resulting in that, as shown in FIG. 13, portions of the inner bag 51 adhere closely to each other to create an independent compartment 54 within the inner bag and that the liquid 52 in the compartment 54 stays therein without being withdrawn, and the amount thereof is not constant.
In the case of liquid suction using a pump, there arises unevenness between the amount of liquid discharged in the initial stage and that in the latter-half stage, and thus it has so far been impossible to withdraw the liquid from the inner bag in a constant volume from beginning to end.